Health Services Utilization and Cost of Retinitis Pigmentosa

Abstract

Retinal dystrophies are characterized by degeneration of photoreceptor and retinal pigment epithelium cells and are the major cause of incurable hereditary blindness in the Western world.¹ Retinitis pigmentosa (RP) is the most frequent cause of inherited visual impairment (VI), with a prevalence of 1:4000, and is estimated to affect 50 000 to 100 000 people in the United States and approximately 1.5 million people worldwide.^2,3 Manifesting initially with a deficiency in night vision, the course of RP is characterized by deterioration of specialized light-absorbing cells in the retina, leading to progressive loss of peripheral and day vision and, over decades, in most cases, severe VI or blindness. Age at onset can vary from early childhood to adulthood, with photoreceptor degeneration often present several years before a patient reports visual symptoms.⁴ Approximately 45 causal genes have been identified in RP, and these account for two-thirds of cases. In general, RP is a progressive disease, with exponential decline in the visual field area of approximately 9% per year and in cone electroretinographic amplitude of 10% per year.^3,5-9